This backend works like the Plain backend but allows to specify mOTP Tokens for users. All users who have a token assigned need to add the time-based 6-digit code to their password upon login. A code is only valid for 10 seconds and can be used only once. Mobile-OTP is a free implementation of a token algorithm - generator programs are available for Java-capable mobile phones, Windows Mobile, iPhone and some other.
The latest update brings time fetching from an NTP-server. So it doesn't depend on your server's clock anymore (which was way off on the server of my hoster).
Please see Installation instructions and changelog.
Please report problems here.